Cardiac expression of NBCn1 variants. (A) Northern blot of rat tissues probed to nucleotides 964–1,334 (encoding N-terminal cassette II) of NBCn1. H, heart; B, brain; S, spleen; Lu, lung; Li, liver; Sk, skeletal muscle; K, kidney; T, testis. (B) PCR of rat whole heart. Primers were designed from the conserved flanking regions of cassette II. The 1.0 kb PCR product represents NBCn1 without cassette II, and the 1.5 kb product represents the one with the cassette. (C) PCR of human cardiovascular system. Primers were designed to amplify a 1.1 kb product for NBCn1 without cassette II and a 1.5 kb product for the one with the cassette. M, molecular marker; IV, interventricular; AV, Atrioventricular. L and R in parenthesis are left and right.